Pre-treatment with the femtosecond laser in eyes undergoing cataract surgery can induce miosis. The use of a pupil expansion device, however, offers an effective method for managing small pupils in femtosecond laser-assisted cases whether the problem pre-exists or is caused by the laser, said Boris Malyugin, MD, PhD.
“Achieving and maintaining sufficient mydriasis is important to prevent complications during cataract surgery,” said Dr. Malyugin, professor of ophthalmology and deputy director, S. Fyodorov Eye Microsurgery Institution, Moscow. “Many ocular and systemic comorbidities affect pupil size, and we have learned that treatment with the femtosecond laser, which induces release of prostaglandins into the aqueous humor, is also a cause of intraoperative miosis.”
Miosis induced after femtosecond laser pre-treatment for cataract surgery was studied by Dr. Malyugin in a series of 47 eyes of 47 patients undergoing surgery for senile cataracts. The patients ranged in age from 57 to 76 years (mean 71.3 years) and had no ocular or systemic comorbidities.
A preoperative medication regimen for achieving and maintaining sufficient mydriasis was part of the surgical protocol, comprised of a topical NSAID (diclofenac sodium 0.1%) applied 3 times per day starting a day before surgery plus cyclopentolate 1% and phenylephrine 2.5% applied at 60, 45, and 30 minutes preoperatively.
Pupil diameter measurements immediately before and 10 minutes after femtosecond laser treatment using a single system (LenSx Laser System, Alcon Laboratories) showed a statistically significant decrease (mean -1.56 ± 0.73 mm) from a mean of 7.79 ± 0.86 mm to 6.42 ± 1.16 mm. In 11 eyes (23.4%), the pupil diameter decreased to ≤ 6 mm and there was a decrease to ≤ 5 mm in 6 eyes (12.7%), he noted.
“Patient compliance with use of the NSAID before surgery was not checked,” he said.